丙烯酰胺诱导人白血病HL-60和NB_4细胞hprt基因的分子突变谱

为了研究丙烯酰胺的遗传毒理作用 ,采用单细胞克隆培养 ,双向筛选计数 ,多重PCR扩增与电泳分析 ,研究了诱导HL 6 0和NB4 两种细胞hprt基因突变率及分子突变谱 .发现只有丙烯酰胺高剂量组 (70 0mg·L- 1)才对两种细胞有明确的致hprt基因突变作用 ;丙烯酰胺诱发突变主要由点突变和缺失两部分组成 (40 .0 %～ 6 6 .7% ,33.3%～ 6 0 .0 % ) ,而自发突变几乎全是点突变 (90 .0 %以上 ) ,两种细胞均无全基因缺失型 ;缺失突变可以发生于hprt基因上的每个外显子 (除外显子 7/ 8以外 ) ,较集中于基因的 3′末端 ,且诱发突变中绝大多数是点突变与单个外显子缺失 (93.3% ,86 .1% ) ,两种细胞情况类似 .结果提示 ,丙烯酰胺具有较弱的诱导hprt基因突变的作用 ,且诱发突变与自发突变的分子图谱不一样 ,这可能与其作用机理有关

Molecular spectra of acrylamide-induced mutation at hprt locus in human promyelocytic leukemia HL-60 and NB4 cell lines

The genotoxicity of acrylamide was investigated by methods of single cell clone culturing, two-way screening count, multiplex PCR amplification and electrophoresis technique. Acrylamide only showed clear mutagenesis until dose 700 mg·L^-1 in HL-60 cells. The most frequent spontaneous mutation was point mutation(≥90.0%) and acrylamide- induced mutation mainly included partial deletion and point mutation(respectively 40.0%－66.7%, 33.3%－60.0%). Total gene deletion was not discovered in both of cells. There was deletion mutation in all exons of hprt gene(except 7/8 exon), and toward the 3 ′ end of the hprt gene. The most frequent acrylamide- induced mutations were point mutation and single exon deletion(93.3%, 86.1%). There was no clear difference in both of cells. The results suggest that the spectra of spontaneous and acrylamide-induced mutants are different, and the smaller changes in genetic structure have something to do with mechanism.